This change is a prerequisite to D3D pipeline caching.
This change introduces:
- Caching interface which enables the cache.
- Helper for backends to load/store blobs to be cached.
- Ability to cache HLSL shaders.
Bug:dawn:549
Change-Id: I2af759882d18b3f45dc63e49dcb6a3caa1be3485
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/32305
Commit-Queue: Bryan Bernhart <bryan.bernhart@intel.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>